1. Field of the Invention
The present invention relates to a solid-state imaging device, and particularly, to a CCD (Charge Coupled Device) solid-state imaging device, a method of manufacturing a solid-state imaging device, and a method of driving a solid-state imaging device. In addition, the present invention relates to an electronic apparatus using the solid-state imaging device.
2. Description of the Related Art
For some time, in a solid-state imaging device, various methods have been contrived in order to realize an imaging function having a wide dynamic range. As a method widely used among them, Japanese Unexamined Patent Application Publication No. 2003-219281 discloses a method of obtaining a wide dynamic range of signals in such a manner that a short second exposure and a long second exposure are performed, and a low sensitive signal and a high sensitive signal having different exposure periods are combined with each other using a calculation.
FIG. 11 shows a driving timing chart of a solid-state imaging device of the related art which uses plural signals having different exposure periods. The timing chart shown in FIG. 11 is the timing chart applied to a CCD-type solid-state imaging device in which a transmission type is an IT (Interline Transfer) type, and a reading type is an entire pixel reading type.
As shown in FIG. 11, the short second exposure is started by the application of the substrate shutter pulse (a in FIG. 11). The signal charge generated by the short second exposure is read to the vertical CCD by the application of the reading pulse (b in FIG. 11). Subsequently, in the vertical CCD, the signal charge obtained by the short second exposure is transmitted in the vertical direction by the vertical transmission pulse (c in FIG. 11). During a period in which the signal charge generated by the short second exposure is transmitted in the vertical CCD, the long second exposure is started by the application of the substrate shutter pulse (d in FIG. 11). Subsequently, after the signal charge generated by the short second exposure is completely transmitted by the vertical CCD, the signal charge generated by the long second exposure is read to the vertical CCD by the application of the reading pulse (e in FIG. 11), and is transmitted in the vertical direction by the vertical transmission pulse (f in FIG. 11).
However, in an operation of driving the solid-state imaging device of the related art, in the case where the long second exposure is shorter than the field period, the end of the long second exposure is determined by the timing of the reading pulse indicated by e in FIG. 11. That is, since it is possible to read the signal charge generated by the long second exposure by using the vertical CCD after the signal charge generated by the short second exposure is completely transmitted in the vertical CCD, the position of the timing of the reading pulse indicated by e in FIG. 11 is fixed.
For this reason, the start of the long second exposure is determined by the substrate shutter pulse. However, after the short second exposure, the substrate shutter pulse is applied in accordance with the reading pulse indicated by e in FIG. 11, and the long second exposure is started as indicated by d in FIG. 11. Accordingly, a time interval exists between the short second exposure and the long second exposure. In this case, it is not desirable to capture an image of a moving object due to a problem in calculation. That is, the time interval between the short second exposure and the long second exposure causes a problem in calculating a wide dynamic range of signals from a moving object.